Just hours before 48 congressional staffers received the anthrax vaccine
Thursday, officials at the Centers for Disease Control and Prevention had
yet to finish the paperwork that would lay out the risks and benefits of
the shots.

The late-night session Wednesday to finalize consent forms for the
inoculations exemplifies the pressure federal officials faced as they tried
to implement their unprecedented vaccination plan this week.

With Hill staffers about to leave for the holidays, CDC officials raced to
get needed approvals that would enable them to offer the vaccine to anyone
who requested it. A CDC board responsible for reviewing patient protections
in research wrapped up its work on the vaccine proposal between 9 and 10
p.m. Wednesday, by CDC accounts. By the start of Thursday's workday at 10
a.m., four dozen Hill staffers who had been exposed to anthrax were
receiving the first of three shots they will get over the next month in the
vaccination program.

The groundwork for the anthrax inoculation program had been laid in
October, when the CDC submitted an application to the Food and Drug
Administration. It proposed providing vaccine and extra doses of
antibiotics to people known to have been exposed to anthrax spores.

The CDC needed FDA clearance because its proposed use of the vaccine and
extended use of antibiotics were new and had not received a formal
government review. In addition, the vaccine's maker, BioPort Corp., has yet
to receive FDA approval for its manufacturing facility.

Between Oct. 5 and this week, the CDC amended its plan four times,
including significant changes to the consent forms. In its Oct. 5 filing,
the CDC endorsed the vaccine in its consent form, saying it "can prevent
anthrax disease" and, used with antibiotics, "could save your life."

The final versions of the forms released Thursday are much more
constrained. They state that the Department of Health and Humans Services
is not "making a recommendation whether you should or should not take this
vaccine" and that "you should not consider the vaccine as treatment for
anthrax."

The original request seeking FDA approval was made when federal health
officials were worried about an influx of new cases, CDC Director Jeffrey
P. Koplan said, adding that having the application pending positioned the
agency to move more quickly as events evolved.

Offering the vaccine to those already exposed "wasn't an option that sprang
to mind then," Koplan said.

FDA regulations require the agency to review applications for
investigational uses of new drugs within 30 days, which helps explain the
seeming haste in the plan, Mary Pendergast, a former deputy at the FDA,
said. And it is not uncommon for the FDA and the sponsor of a proposed drug
test to have back-and-forth discussions about how to bring a proposal into
compliance with FDA rules.

But she also noted that federal agencies "appear to have given themselves a
deadline of making the vaccine available before Congress went out for the
session so that put them up against the clock."

As part of its FDA application, the CDC was required to estimate how many
people would be eligible for the vaccine and how it would be administered.
The application also had to present a proposed informed consent sheet that
subjects in the vaccine program would receive.

The first version of the plan estimated between 100 and 5,000 people could
be eligible, while acknowledging an unforeseen scenario could drive the
number higher. The final version estimates between 100 and 10,000 people
could be eligible, barring an unforeseen event.

CDC officials say that the speed with which the proposal was developed and
approved reflected the fluidity of the crisis.

"Some of these individuals may have been more highly exposed than what we
once thought -- that's where the urgency comes from," CDC spokesman Tom
Skinner said. Scientists, he said, are also theorizing that small numbers
of spores might persist in some individuals who have been heavily exposed
and could burst into a lethal infection once a 60-day course of antibiotics
-- as exposed workers already have been offered -- was completed.

Skinner said that CDC's most recent amendment to the application followed
the release of results from a Canadian experiment, in which a test subject
sat in a room about the size of a single-car garage and slit open an
envelope filled with nontoxic bacteria and lay the open envelope down on a
table. Sensors and tests evaluated how many of the spores from the bacteria
were released into the air and how many got in the volunteer's body.

Greg Martin, an infectious diseases expert at the National Naval Medical
Center who has been helping treat Senate staffers who had been exposed to
anthrax, said that the Canadian results caused researchers to recommend the
vaccinations.